Idris Nasrullah, Lahna Kurnia, Ramli Muliadi, Abidin Taufik Fuadi, Budi Wahyu Setia, Suliyanti Maria Margareta, Kurniawan Koo Hendrik, Tjia May On, Kagawa Kiichiro
Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh, 23111, Aceh, Indonesia.
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh, 23111, Aceh, Indonesia.
Heliyon. 2020 Dec 16;6(12):e05711. doi: 10.1016/j.heliyon.2020.e05711. eCollection 2020 Dec.
Laser induced breakdown is a highly temporally and spatially dynamic phenomenon, normally studied using a highly temporally resolved optical detector system. In this work, a compact, low cost optical multichannel analyzer (OMA) system without a built-in temporal gating device and thus operated under a free running mode was used to investigate the characteristics of laser induced plasma. A Nd-YAG laser beam was used as the excitation source from several samples, namely, copper, zinc, and aluminum plates. The characteristics of the plasma emission produced under various experimental parameters, including the pulse energy, surrounding gas pressure, and collection fiber position, were examined. It was found that the essential features of emission spectra can be investigated even using the ungated, compact OMA system even without a highly temporally resolved gating system. The plasma emission characteristics critically depend on the experimental parameters. A quality emission spectrum, featuring a high intensity with a low background, can be obtained using the ungated, compact OMA system under optimized conditions, namely, a pulse energy of approximately 8 mJ, a surrounding gas pressure of 10 Torr, and a collection fiber position of more than 5 mm above the surface of the sample. The features of the emission spectra detected under optimized conditions are only similar to those obtained using a sophisticated, gated OMA system. The characteristics of the emission spectra are in good agreement with the previous assumption of the shockwave role in plasma excitation. Having quality emission spectra under the optimized conditions, a preliminary practical laser induced breakdown spectroscopy (LIBS) analysis using the ungated, compact OMA system was performed on several samples, such as standard brass, commercial pure gold, and natural stone samples. The aluminum emission lines are strongly detected from the standard brass sample (C1118) containing aluminum at 2.8%. The LIBS system also unequivocally revealed a qualitatively abandoned impurity presence in the purportedly pure commercial gold sample. It also effectively confirmed qualitatively a Cu presence in the blinking spots of the natural stone collected from a traditional mining site in Aceh. This result implies the effectiveness of the LIBS using the ungated, compact OMA system for quick, practical analysis.
激光诱导击穿是一种在时间和空间上高度动态的现象，通常使用具有高时间分辨率的光学探测器系统进行研究。在这项工作中，使用了一种紧凑、低成本的光学多通道分析仪（OMA）系统，该系统没有内置时间选通装置，因此在自由运行模式下运行，用于研究激光诱导等离子体的特性。使用Nd-YAG激光束作为来自几个样品（即铜板、锌板和铝板）的激发源。研究了在各种实验参数（包括脉冲能量、周围气体压力和收集光纤位置）下产生的等离子体发射特性。结果发现，即使使用无门控的紧凑型OMA系统，即使没有高时间分辨率的选通系统，也可以研究发射光谱的基本特征。等离子体发射特性严重依赖于实验参数。在优化条件下，即脉冲能量约为8 mJ、周围气体压力为10 Torr以及收集光纤位置在样品表面上方超过5 mm时，使用无门控的紧凑型OMA系统可以获得具有高强度和低背景的高质量发射光谱。在优化条件下检测到的发射光谱特征仅与使用复杂的门控OMA系统获得的特征相似。发射光谱的特征与先前关于冲击波在等离子体激发中的作用的假设高度一致。在优化条件下获得了高质量的发射光谱，使用无门控的紧凑型OMA系统对几个样品（如标准黄铜、商业纯金和天然石材样品）进行了初步的实际激光诱导击穿光谱（LIBS）分析。在含铝量为2.8%的标准黄铜样品（C1118）中强烈检测到铝发射线。LIBS系统还明确揭示了在所谓的纯商业金样品中存在定性废弃的杂质。它还有效地定性确认了从亚齐传统矿区采集的天然石材的闪烁点中存在铜。这一结果表明使用无门控的紧凑型OMA系统进行LIBS快速、实际分析的有效性。
